Figure 2

Minimum evolutionary tree for MHC DRB exon 2 alleles of Brandt’s voles. The tree is based on nucleotide sequences (Kimura 2-parameter). Bootstrap values (>50) are displayed (1000 replications). The scale bar indicates genetic distance in units of nucleotide substitutions per site. Dog, cat, sheep, and human DRB exon 2 sequences were used to root the tree. GenBank accession numbers follow the species designations. Alleles found in the MD region alone are indicated by squares, those in the DWQ region alone are indicated by triangles, and those in both regions are indicated by diamonds.